1. Field of Invention
The invention relates to an electrical apparatus and, in particular, to an electrical apparatus, which has illumination device in dark environment.
2. Related Art
As the coming of the electronic age, the dependences and demands of people on the electrical products have greatly grown. Since the market trends mostly depend on the customers, the preferred products should not only have competitive prices, but also be equipped with conveniences in characteristics and usages. Therefore, the manufacturers usually work hard to create the products filling the customer's needs.
Taking a computer as an example, when the operation environment has insufficient light or is dark, a user usually cannot distinguish all buttons clearly, which results in the inconvenience of the operation. In view of this, a conventional solution is to install an internal light source in the keyboard 1, as shown in FIG. 1. The keyboard 1 includes a plurality of buttons 11, each of which is composed of a button cap 111, a transparent top plate 112 and a rubber pad 113. A light-guiding plate 12, which has the same area as the keyboard 1, is disposed under the buttons 11. A plurality of light sources 13 are installed at the periphery of the light-guiding plate 12, and are used as a backlight. The light sources 13 are driven with electric power through the wire 14. With the light emitted from the backlight, the buttons 11 can be illuminated in the dark environment. However, the above-mentioned method employs the light-guiding plate with a large area and several light sources, which increase the manufacturing cost.
Alternatively, one of ordinary skill in the art may use an extra lamp with an USB connecter for illuminating the keyboard. However, this solution is more complex in usage, and does not match the trend of convenience.
In addition, the present keyboard is used only for inputting instructions and is not designed for user's vision. For example, changing the color and luminance of the light of the keyboard may satisfy the user's vision.
It is therefore a subjective of the invention to provide an electrical apparatus, which can solve the above-mentioned problem of clearly distinguishing buttons in dark environment.